PSYC1002 Lecture Notes - Lecture 9: Myelin, Depolarization, Action Potential

• School: University of Sydney
• Department: Psychology
• Course: PSYC1002
• Professor: Caleb

Document Summary

Understanding how neurons work can help us understand what information they carry turns out to be very simple, and not unlike electric circuits! They send (cid:271)i(cid:374)ary (cid:894)(cid:862)o(cid:374)(cid:863)/(cid:863)off(cid:863)(cid:895) sig(cid:374)als to ea(cid:272)h other: neurons are covered in lipid (fatty) membrane (like a plastic skin, the membrane is semipermeable, allowing the neuron to control the concentration of positively and negatively charged ion inside it. In its normal resting state, the inside of the neuron is negatively charged compared to the outside, which has positively charged sodium ions in this state, the neuron is polarised. The action potential (all or none: at specific moments (lasting only a few milliseconds), the neuron can open channels that let ions enter and exit. Propagation of action potential: action potential is localised to small segment of membrane and spreads along membrane, hyperpolarisation after action potential prevents it from moving back onto itself.